Installations of the aforementioned kind are known in which the plough is provided with a drive plate, the socalled sword plate, projecting beneath the conveyor. The drive plate is coupled to a chain running inside guide passages at the goaf side, i.e. the side of the conveyor remote from the mineral face. The passages are defined by a structure which includes detachable covers which screenoff the passages laterally. The covers can be removed for access purposes. The drive plate slides on skid plates resting on the floor and forming a sub-frame beneath the conveyor. As the drive plate moves beneath the individual channel sections or pans it raises these to a limited extent relative to the sub-frame as it passes. To accommodate this movement it is known from German Patent Specification No. P 1 205 927 to form pivot connections between the covers and the sub-frame structure.
It is also known to provide upstanding brackets on the sub-frame which are linked to the covers with pivot joints. Another known installation of this type is described in German Patent Specification No P26 21 382. This installation has upstanding flanges on the sub-frame which themselves cover the chain guide passages laterally and which are articulated to the conveyor pans. Advancing rams and hydraulic control units for controlling the attitude of the plough can be connected to flanges or to the brackets in these known constructions.
The prior art installations suffer from certain disadvantages. The passage of the plough drive plate is not always reliably accommodated especially where the floor or the working is uneven. The access to the drive chain in the guide passages is not easily facilitated especially in the cramped conditions encountered in shallow seams where space to manoeuvre the components is restricted. Also under such conditions it is difficult to keep the installation within a sufficiently low height overall to permit general access for personnel.
A general object of the present invention is to provide an improved mineral mining installation.